The present invention relates to an electronic copying apparatus for forming a toner image of a document to be copied on a photosensitive medium.
An electronic copying apparatus of this type is generally classified into two types of the apparatus. One type of the copying apparatus forms a toner image of a document to be copied on a photosensitive medium, transfers the toner image to a copy paper, and then fixes the toner image transferred onto the copy paper, and then fixes the toner image transferred onto the copy paper. The other copying apparatus uses the photosensitive medium for a final copy paper. A toner image of the document is formed on the copy paper and is fixed theron. A description of a prior art copying apparatus of the former type, in which the toner image formed on the photosensitive medium is transferred onto the copy paper, will be given. The copying apparatus of this type is comprised of a document holding device for holding a document to be copied, a scanning device for scanning the document by relatively moving the document holding device and an exposure device, a latent image forming device for forming a latent image of the document on the photosensitive medium, a developing device for forming a toner image of the latent image, and a transfer device for transferring the toner image to a copy paper, and a fixing device for fixing the toner image on the copy paper. To complete one cycle of the copying operation, the document held on the document holding device is scanned one time by the scanning device. A single latent image corresponding to one time of scanning is formed by the latent image forming device. After the single toner image is transferred to a single copy paper, the toner image transferred is fixed on the copy paper. Thus, the toner image on the copy paper represents the image of the document corresponding to the one-time scanning.
There frequently occurs a situation that a number of documents of a much smaller area than that of the copy paper must be copied. In such a situation, if the small area document is copied by using the prior copying apparatus, the copy paper has a large useless space. To solve the useless space problem, a plurality of copied images formed through a plurality of transferring steps which produce the useless space on the copy paper are pasted together to form a new copy paper of a large area including a plurality of the copied images. The new document thus prepared must further be copied.